Tumors associated with hypoglycemia:
(1) hemangiopericytoma
(2) solitary fibrous tumor
(3) meningioma
(4) other
Clinical and laboratory features:
(1) The patient presents with unexplained hypoglycemia.
(2) Serum insulin, C protein, growth hormone and insulin-like growth factor I are greatly reduced.
(3) A tumor is identified on imaging studies.
(4) The hypoglycemia parallels extent of tumor size, becoming more severe as the tumor enlarges, regressing on complete surgical resection, and reappearing with tumor recurrences.
(5) The tumor secretes a protein with insulin-like activity, often insulin-like growth factor II (IGF II) or a precursor form of IGF-II with a higher molecular weight ("big" pro-IGF II).
Differential diagnosis:
(1) carcinoid tumor, with production of insulin
(2) excessive glucose consumption
(3) impaired hepatic gluconeogenesis
(4) other causes of hypoglycemia
